Transmission regulation



March 23, 1937. Q B, WR|G||| TRANSMISSION REGULATION Filed March 7, 1936 Wsw 5.5. wig/w Patented Mar. 23, 1937 i UNITED STATES PATENT GFFICE 2,074,446 TRANSMISSION REGULATION Sumner Bisbee Wright, South Orange, N. J., assignor to Bell Telephone Laboratories, IncorpYoraIted, New York, N. Y., a corporation of New Application March "l, 1936, Serial No. 67,723 8 Claims. (Cl. 178-44) This invention relates to a system for controlmission regulator as an example of such other ling circuit switching and other operations by uses. Wave controlled devices. One application of this Further features and principles of the invention principle is to control the operation of an autowill be understood from the following description matic transmission regulator or gain changer when read in connection with the accompanying although many other applications will readily drawing, the figure of which illustrates a presuggest themselves. ferred form of the invention.

It is well known in the art that telephone Waves In the drawing there are foul WaVe transmitin one direction of transmission that are proters. T1. T2y T3 and T4, Capable of impressing sigio duced by conversation are not continuous but ocnale On the lines. L1, L2, L3 and L4, Which are l0 cupy only about one-third of the holding time. connected t0 delay elements D1, D2, D3 and D4 The other two-thirds is occupied by pauses bethrough wave operated magnets A1, Az, As and A4. 'tween syllables and by answering from the dis- These delay elemente` may he magnetic reccldtant end. In the transmission regulation system ing tapes or other similar recording mechanisms.

herein described the circuits are so arranged that The output magnets B1, B2, B3 and B4 of the 15 the transmission regulation Will take place only delay elements are connected to potentiometers during intervals when no transmission is taking Pi, P2, P3 and P4 ahead of amplifiers Which Supplace over the circuits involved. ply the regulated waves to other lines Li, etc.,

Transmission regulators, as heretofore devised, and receiving deViCeS H1, etc- Magnets E1, E2.

have involved the principle of adjusting the trans- Es and E4 are supplied With dileet current S0 aS 20 mission level of the signaling channel whenever to erase the pattehS 0f the Speech WaVeS after the transmission level departs more than a given theyv have been Suitalcli7 delayed between the A amount from a normal desired level. A comand B magnets. mon mechanism for effecting this result is the The four potentiometers are controlled by the so-called pilot regulator in which one of the operation of a magnetic clutch connected to their 25 channels of a group of channels is Set aside as Shaft, illustrated aS Ps With aSSOciated magnets a pilot channel. Whenever the transmission con- Ci and C2. The magnets are supplied with batditions on this particular channel become abnortery Si through the contacts of the wave opermal, the pilot regulator becomes effective to make ated magnets and are supplied with ground by compensating adjustment upon each of the other operation of a galvanometer connected to a' 30 channels of the group on the assumption that the Wheatstone. bridge, one arm of which may be a same abnormal conditions apply to allof the line designated aS a pilot Wirechannels. Typical operation of transmission regulating In accordance with the present invention the systems is disclosed in detail elsewhere as, for

pilot regulator is under the joint control of the example, in U- S. Patents N0S- 1,438,217 t0 1,433,- 35

pilot channel and the channels to be regulated. 220, inclusive, iSSued t0 A- B- Clalk Brieflyy i11- Each of the channels to be regulated is provided crease in resistance of the pilot wire due to the with an arrangement which will defeat the operatemperature rising results in unbalancing the tion of the pilot regulator during such times as Wheatstone bridge SO that Current iS fed from 4 0 the signals are being transmitted over the chanbattery S2 through the galvanometer which is 40 nel. When an interval Occurs, however, in which Operated in One di1`ecti0n 01 the Other- In the no signals are being transmitted over any of the dIaWihg it iS assumed that thi-s OperatiOn cauSeS channels to be regulated, the pilot regulator is ground t0 be applied t0 Clutch magnet C1 Opera released for operation. If the pilot channel indi.. tich 0f `Which WOllld cause the potentiometers to Cates an abnormal transmission level the mgm rotate in a clockwise direction. This rotation 45 lator operates to make the compensating adjustof the potentlometers asspcta'ted with .the te' ment peaters Iiiuldb cause tle gasinginftlrietircuitrto m crease, ere y comp nsa 1n o e mc ease This method of Yom? Opelated Control can also transmission loss due to the rising temperature.

be use d to, Select qinet ,lnterva1s-f0r any other type In addition, the movement of the potentiometer 50 of Wltchmg O1' aucun" Changmg that might be P5 would transfer resistance from Rb to Rc, theredesired. Furthermore, other types of signals by balancing the bridge and putting the salvar i such as telephoto or television signals can be used nometer in a neutral position, thus removing t0 Operate the ccntlcl. The drawing ShOWS an ground from the clutch. When the temperature application to the control of an automatic transdecreases the action is similar except that clutch 55 Cz is provided with ground necessary for its operation.

The magnetic clutches, however, require that battery S1 be connected in order for the above operations to take place. In the drawing it is assumed that waves are traversing line L1 and delay circuit D1, thereby holding magnets A1 and B1 operated. Thus battery S1 is not connected to the clutches and the shaft will not rotate even though the Wheatstone bridge be unbalanced and the ground connected to one clutch or the other.

As soon as the waves have passed the delay element D1, and magnets A1 and B1 are consequently released, the battery connection is established and the shaft is caused to rotate. Wave transmission in any of the other lines would similarly hold up the operation until transmission in all circuits had ceased. This would improve the transmission in that adjustments of the gain would not be made at a time when waves were being transmitted over the circuit.

It will be obvious that the general principles herein disclosed may be embodied in many other organizations widely different from those illustrated without departing from the spirit of the invention as dened in the following claims.

What is claimed is:

1. In a signaling system, a signal transmission channel, a similar channel responsive to changes in the transmission level, means responsive to a change in the transmission level of said similar channel to restore the transmission level of said signal channel to normal, and means responsive to signal currents transmitted over the channel to prevent the operation of said restoring means.

2. In a signaling system, a plurality of more than two transmission channels, means to restore the transmission level of each of said channels to normal when the transmission level is abnormal, and means operating when signals are being transmitted over any of the channels to prevent the operation of said restoring means with respect to all of the channels.

3. In a signaling system, a plurality of more than two transmission channels subject to common influences which affect their transmission levels, one of said channels being used as a pilot channel, means controlled by said pilot channel for making compensating adjustments in the transmission levels of each of the other channels at times when an abnormal transmission condition exists in the pilot channel, and means operating when signals are being transmitted over any of the other channels to prevent the operation of said restoring means with respect to all of the channels.

4. In a signaling system, a plurality of more than two transmission channels subject to common influences which affect their transmission levels, one of said channels being used as a pilot channel, and means under the joint control or said pilot channel and each said other channels to make a compensating adjustment of the trans mission levels of all of said channels when the transmission is abnormal.

5. In a signaling system, a plurality of more than two transmission channels subject to common iniluences which aiect their transmission levels, one of said channels being used as a pilot channel, means controlled by said pilot channel for making compensating adjustments in the transmission levels of the other channels at times when an abnormal transmission condition exists in the pilot channel, and means jointly controlled by each of said other transmission channels to prevent the operation of said pilot controlled means when signals are being transmitted over said other channels.

6. In a signaling system, a plurality of more than two transmission channels subject to common inuenoes which aeot their transmission levels, one of said channels being used as a pilot channel, means controlled by said pilot channel for making compensating adjustments in the transmission levels of the other channels at times when an abnormal transmission condition exists in the pilot channel, and each of said other transmission channels having associated therewith means to prevent the operation of said pilot g controlled means when signals are being transmitted over the channel.

7 In a signaling system in which a plurality of more than two signaling channels are so arranged that their transmission levels may be adjusted when an abnormal transmission condition exists in a common pilot channel, the method which consists in preventing a level adjustment in any of the channels until there is no energy above a predetermined value in any of the channels of the system.

8. In a signaling system in which a plurality of more than two signaling channels are so arranged that their transmission levels may be adjusted when an abnormal transmission condition exists in a common pilot channel, the method which l consists in preventing a level adjustment in any of the channels until a condition Occurs during which no signals are being transmitted over any of the channels of the system.

SUMNER BISBEE WRIGHT. 

